He has previously accused Sun of being a “drug cheat”. Sun denies recent claims he violated doping protocols.

Governing body Fina also warned Australian officials over the protest.

“While Fina respects the principle of freedom of speech, it has to be conducted in the right context,” it said, adding that athletes should not “use Fina events to make personal statements or gestures”.

After claiming silver on Sunday, Horton stood apart from Sun and did not shake hands with him. He also declined to take photos with Sun, but posed beside Italian bronze medallist Gabriele Detti.

Horton had said he felt “frustration” after the race, adding: “I think you know in what respect… His actions and how it has been handled speaks louder than anything I could say.”

Sun responded by telling reporters that “disrespecting me was OK, but disrespecting China was unfortunate”.

Furious response

Since the race, Horton’s social media accounts have been flooded with messages of criticism and abuse by Sun’s fans.

The response echoes a similar online backlash against Horton when he first publicly criticised Sun at the 2016 Rio Olympics.